hh: Better scaling values

 * Default slack is too long and boost is too high, these values
   collide. Fix them.
 * Set a better timer_rate to reduce jitter

Change-Id: Id99c1642ca38d184e75d09bd3afc71951a8801c0
Merge branch 'cm-11.0' of https://github.com/CyanogenMod/android_device_lge_hammerhead into cd-4.4